I just came across this paper ( https://www.frontiersin.org/articles/10.3389/fnins.2020.536682/full ) which is about the complexity of astrocyte metabolism, which in turn affects brain metabolism. There are all sorts of metabolic processes going on in those cells, affecting other brain cells, so even a minor dysfunction there could result in disruptions in other brain functions. The effects can be regional, which could explain why ME varies so much. This fits into this thread, since astrocytes control the hypothalamus too.